The invention relates to a socket for connecting a plug in the external region of a motor vehicle, comprising a socket housing, in which a plug-receiving opening having electric contacts for plugging in a plug and establishing an electric connection is formed, and comprising a cover, which is hinge-mounted on the socket housing and closes the plug-receiving opening in the closed position of the cover and which is preloaded in the closing direction. In the closed position, a seal accommodated in the cover interacts with the edge of the plug-receiving opening, as a sealing surface, thereby preventing water from entering the plug-receiving opening when the socket is not connected to a plug and the plug-receiving opening is covered by the cover.
Covers that are hinge-mounted on the socket housing are usually supported on a hinge and are loaded in the closing direction with the aid of a leg spring. For this reason, the moment acting in the closing direction on the cover is greater in the open position than in the closed position of the cover. In a completely or partially open position of the cover, the spring force of the leg spring must be just high enough to allow the cover to close when released. In order to improve the seal integrity of the socket between the closed cover and the wall of the plug-receiving opening, it is absolutely desirable for the spring force to also be as high as possible in the closed position of the cover. This could be achieved by way of a sufficiently strong leg spring that, however, would develop a closing force in the open position of the cover that is so great that a considerable risk of injury exists when the cover in the open position is accidentally released and a finger is clamped between the cover and the socket housing. In order to minimize the risk of injury, the closing force of the cover is limited in sockets currently on the market.
In practical application, especially when the sockets are used in the field of agriculture or in trucks, this results in problems of seal integrity since trucks and agricultural devices often become very dirty during use and may be cleaned using high-pressure cleaners. The force of the water jet can potentially lift the cover out of the closed position thereof, thereby allowing moisture to enter the contact region of the socket, which can cause short circuits in subsequent use. Water entering the interior of the socket can also result in unwanted corrosion of the electric contacts.
The problem therefore arose of providing a socket that results in an improved hold of the cover in the closed position of the cover. According to an important application, the seal of the contact region is improved by way of an increased closing force of the cover bearing against the wall of the plug-receiving opening.